Angier,
I use a switch between bus voltage and a 5V voltage regulator to feed the trim servo.  Bob's point is a valid concern any time voltage is cut.  In our case (360 MKII tail), the gear ratio is very high and the actual motor torque required very low.  Here is a video of the trim tab speed in high and low rates.
http://www.n91cz.com/VideoClips/TrimTabDualRate_0001.wmv
1,450 hours on this system without any issues.
I do use a pulsing speed control on my hefty avionics cooling fans.

Chris Zavatson
N91CZ
360std
www.N91CZ.net




On Mar 28, 2013, at 7:07 AM, "Greenbacks, UnLtd." <N4ZQ@VERIZON.NET> wrote:

> My elevator trim on at pattern speeds works well but is way too sensitive
> at high speed. Ray Allen makes a speed control and I'm curious to know if any of you
> have tried it. Any other solutions out there?
>
> Angier Ames
> N4ZQ
> --
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